Industrial vehicle

ABSTRACT

An engine exhaust system is accommodated in a counterweight portion without reducing either the efficiency of cooling by a radiator or the efficiency of purifying exhaust gas by an exhaust gas purification device. A body has a work device provided at the front and the counterweight portion at the rear. A ventilation path provided in the counterweight portion includes an elevated part formed between a bottom of a front portion and a bottom of a rear portion. The purification device and a muffler are disposed in the rear portion of the ventilation path so as to be positioned one above the other with the purification device lying above the muffler and having an upper portion protruding above the bottom of the front portion of the ventilation path. A windbreak plate made from a heat insulating material is disposed forward from the purification device so as to face the latter.

TECHNICAL FIELD

The present invention relates to industrial vehicles, particularly to an industrial vehicle, such as a forklift or a shovel loader, which includes an engine as a power source and has a work device attached at the front of a body.

BACKGROUND ART

Some of the industrial vehicles such as a forklift and a shovel loader include diesel engines as power sources. Incidentally, emissions control is applied to diesel engine vehicles, and it is obligatory to reduce hazardous substances in exhaust gas, such as particulate matter (PM), sulfur oxide, and nitrogen oxide (NO_(X)), to standard values or lower. Accordingly, industrial vehicles equipped with diesel engines also have exhaust gas purification devices attached on the upstream side relative to exhaust pipe mufflers of the engines.

For example, conventional forklifts equipped with diesel engines have work devices provided at the front of bodies, and also have counterweight portions provided at the rear of the bodies in order to balance loads on the work devices, and the engines are attached to the bodies and positioned forward from the counterweight portions (see, for example, Patent Documents 1 and 2). Moreover, provided in the counterweight portions are ventilation paths extending in the front-rear direction of the bodies.

Furthermore, there are radiators disposed rearward from the engines so as to be positioned immediately before front end openings of the ventilation paths or at the front of the ventilation paths, and also disposed between the engines and the radiators are radiator fans for cooling the radiators. Accordingly, airflows generated by rotation of the radiator fans are exhausted through the ventilation paths to the outside of the bodies.

Further, the forklifts include exhaust pipes, exhaust gas purification devices and mufflers, in which the exhaust pipes are supported by the bodies, connected to the engines at one end, and protrude from the rear of the bodies to the outside at the other end, and the exhaust gas purification devices and the mufflers are provided at some positions along the exhaust pipes. Typically, the exhaust gas purification device and the muffler have a cylindrical outer shape, and constitute a relatively large component unit in the forklift in the case where the forklift is small.

Still further, the operating temperature of the exhaust gas purification device is considerably high (about 400 to 800° C.), and in addition, the exhaust gas purification device is designed to be heated by exhaust gas and therefore is preferably disposed as close as possible to an exhaust manifold of the engine.

Accordingly, there is an issue as to where in the body to dispose an engine exhaust system, which consists of the exhaust pipe, the exhaust gas purification device, and the muffler, and in this case, for reasons concerned with the structure of the forklift, it is desirable to not change the existing arrangement of the engine, the radiator, the radiator fan, and the counterweight portion on the body (i.e., the positional relationship therebetween).

Therefore, in the conventional art, considering the downsizing of the body, the ensuring of the driver's view, prevention of burns to the driver, easy maintenance of the exhaust gas purification device, etc., the engine exhaust system is accommodated in the counterweight portion, and further, the exhaust gas purification device is disposed so as to face the back of the radiator (see, for example, Patent Documents 1 and 2).

However, although this configuration allows the exhaust gas purification device to be cooled by cooling air directly blowing from the radiator fan that is rotating, the radiator is heated by being subjected to radiation heat straight from the exhaust gas purification device, resulting in an issue of compromising both the efficiency of cooling an engine coolant by the radiator and the efficiency of purifying exhaust gas by the exhaust gas purification device.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Laid-Open Patent Publication No. H08-312335

Patent Document 2: Japanese Laid-Open Patent Publication No. 2012-106836

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

Therefore, the present invention addresses a problem of allowing an engine exhaust system to be accommodated in a counterweight portion without reducing either the efficiency of cooling by a radiator or the efficiency of purifying exhaust gas by an exhaust gas purification device.

Solution to the Problems

To solve the problem, the present invention provides an industrial vehicle including a work device attached at a front of a body, a counterweight portion for balancing a load on the work device, the counterweight portion being disposed at a rear of the body and having a ventilation path provided therein so as to extend in a front-rear direction of the body, an engine attached to the body as a power source and disposed forward from the counterweight portion, a radiator disposed rearward from the engine so as to be positioned immediately before a front end opening of the ventilation path or at a front portion of the ventilation path, a radiator fan for cooling the radiator, the radiator fan being disposed between the engine and the radiator and allowing an airflow generated by rotation of the radiator fan to be exhausted to the outside of the body through the ventilation path, an exhaust pipe supported by the body, connected to the engine at one end, and protruding from the rear of the body to the outside at the other end, and an exhaust gas purification device and a muffler provided at some positions along the exhaust pipe, in which, the exhaust gas purification device and the muffler are disposed rearward from the radiator in the ventilation path, either one above the other or side by side in a right-left direction of the body, a windbreak plate for preventing the airflow from blowing onto the exhaust gas purification device is disposed between the radiator and the exhaust gas purification device so as to face the exhaust gas purification device, and the windbreak plate is formed from a heat insulating material.

In accordance with a preferred embodiment of the present invention, an elevated part is formed between bottoms of the front and rear portions of the ventilation path, whereby the bottom of the rear portion is lower than the bottom of the front portion, the exhaust gas purification device and the muffler are disposed in the rear portion of the ventilation path so as to be positioned one above the other with the exhaust gas purification device lying above the muffler and at least partially protruding above the bottom of the front portion of the ventilation path, and the windbreak plate is erected on the bottom of the front portion such that the windbreak plate has an upper end surface positioned higher than an upper end surface of the exhaust gas purification device.

In accordance with another preferred embodiment of the present invention, the exhaust gas purification device and the muffler are disposed one above the other with the exhaust gas purification device lying below the muffler, and the windbreak plate is erected on the bottom of the ventilation path such that the windbreak plate has an upper end surface positioned higher than an upper end surface of the exhaust gas purification device. In accordance with still another preferred embodiment of the present invention, at least an upper portion of the windbreak plate is bent or curved toward the exhaust gas purification device. In accordance with yet another preferred embodiment of the present invention, both the exhaust gas purification device and the muffler have a cylindrical outer shape and extend in the right-left direction of the body.

In accordance with yet another preferred embodiment of the present invention, an elevated part is formed between bottoms of the front and rear portions of the ventilation path, whereby the bottom of the rear portion is lower than the bottom of the front portion, the exhaust gas purification device and the muffler are disposed in the rear portion of the ventilation path so as to be positioned side by side in the right-left direction of the body, with the exhaust gas purification device at least partially protruding above the bottom of the front portion of the ventilation path, and the windbreak plate is erected on the bottom of the front portion such that the windbreak plate has an upper end surface positioned higher than an upper end surface of the exhaust gas purification device. In accordance with yet another preferred embodiment of the present invention, both the exhaust gas purification device and the muffler have a cylindrical outer shape and extend vertically. In accordance with yet another preferred embodiment of the present invention, the industrial vehicle is a forklift.

Effect of the Invention

In accordance with the present invention, the exhaust gas purification device and the muffler of the industrial vehicle are disposed rearward from the radiator in the ventilation path within the counterweight portion, either one above the other or side by side in the right-left direction of the body, the windbreak plate is disposed between the radiator and the exhaust gas purification device so as to prevent an airflow caused by the radiator fan from blowing onto the exhaust gas purification device, and further, the windbreak plate is formed from a heat insulating material. Therefore, the engine exhaust system (i.e., the exhaust pipe, the exhaust gas purification device, and the muffler) of the industrial vehicle can be collectively accommodated in the counterweight portion, and at the same time, while the industrial vehicle is being driven, neither is the exhaust gas purification device subjected to cooling air directly from the radiator fan, nor is the radiator subjected to radiation heat straight from the exhaust gas purification device, whereby unnecessary cooling of the exhaust gas purification device and unnecessary heating of the radiator are minimized, so that the efficiency of purifying exhaust gas by the exhaust gas purification device and the efficiency of cooling by the radiator are not reduced. Moreover, the ventilation path in the counterweight portion is utilized as the space to accommodate the exhaust gas purification device and the muffler, whereby there is almost no need to change existing structures of industrial vehicles, so that the present invention can also be applied to existing industrial vehicles at extremely low costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view illustrating the general configuration of an industrial vehicle in the form of a forklift according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the direction of the central axis of a body of the forklift shown in FIG. 1, outlining the structure of a counterweight portion.

FIG. 3 is an oblique view illustrating main internal components of the counterweight portion shown in FIG. 2.

FIG. 4A and FIG. 4B provide similar views to FIG. 2 and illustrates variants of a windbreak plate.

FIG. 5A and FIG. 5B provide views illustrating variants of the embodiment shown in FIG. 1.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view schematically illustrating the general configuration of an industrial vehicle according to an embodiment of the present invention. In this embodiment, the industrial vehicle is in the form of a forklift, as shown in FIG. 1. Referring to FIG. 1, the forklift has a fork 2 attached at the front of a body 1 as a work device, and a counterweight portion 3 disposed at the rear of the body 1 in order to balance a load on the fork 2. In addition, provided forward from the counterweight portion 3 on the body 1 is an engine (diesel engine) 4 serving as a power source.

FIG. 2 is a cross-sectional view taken along the direction of the central axis of the body 1 of the forklift, outlining the structure of the counterweight portion 3, and FIG. 3 is an oblique view illustrating main internal components of the counterweight portion shown in FIG. 2. Referring to FIG. 2, the counterweight portion 3 has an upper wall 3 a, a rear wall 3 b, and left and right side walls (not shown), and provided in the counterweight portion 3 is a ventilation path 5 extending in the front-rear direction of the body 1 and having a front end opening serving as an air inlet 5 a and a rear end opening serving as an air outlet 5 b. The air outlet 5 b is provided in the rear wall 3 b of the counterweight portion 3.

The ventilation path 5 has an elevated part 14 formed between a bottom 6 a of a front portion 6 and a bottom of a rear portion 7, so that the bottom of the rear portion 7 is lower than the bottom 6 a of the front portion 6. Note that in this embodiment, the bottom 6 a of the front portion 6 of the ventilation path 5 is formed by a part of the surface of a counterweight or body 9, and the ventilation path 5 is open at the bottom of the rear portion 7.

Disposed in the front portion 6 of the ventilation path 5 is a radiator 8 for cooling an engine coolant. The radiator 8 is erected on the bottom 6 a of the front portion 6 of the ventilation path 5 so as to face the air inlet 5 a and the air outlet 5 b. Note that in this embodiment, although the radiator 8 is disposed in the front portion 6 of the ventilation path 5, if necessary, the radiator 8 may be disposed rearward from the engine 4 so as to be positioned immediately before the air inlet 5 a of the ventilation path 5.

Disposed between the engine 4 and the radiator 8 is a radiator fan 10 for cooing the radiator 8. The radiator fan 10 is positioned so as to face the front of the radiator 8, and has a rotating shaft 10 a coupled to the engine 4. The radiator fan 10 is rotationally driven by the engine 4. Accordingly, an airflow is generated by rotation of the radiator fan 10 and exhausted through the ventilation path 5 to the outside of the body 1 from the air outlet 5 b.

The forklift further includes art exhaust pipe 11, an exhaust gas purification device 12, and a muffler 13, in which the exhaust pipe 11 is supported by the body 1, connected to the engine 4 at one end, and protrudes from the rear of the body 1 to the outside at the other end, and the exhaust gas purification device 12 and the muffler 13 are provided at some positions along the exhaust pipe 11. The exhaust gas purification device 12 includes, for example, a diesel particulate filter (DPF), a diesel oxidation catalyst (DOC), and so on.

In this embodiment, both the exhaust gas purification device 12 and the muffler 13 have a cylindrical outer shape. Moreover, the exhaust gas purification device 12 and the muffler 13 discretely extend in the rear portion 7 of the ventilation path 5 in the right-left direction of the body 1, and are positioned one above the other with the exhaust gas purification device 12 lying above the muffler 13 and at least partially (in this embodiment, the upper half) protruding above the bottom 6 a of the front portion 6 of the ventilation path 5.

Although not shown, the exhaust gas purification device 12 and the muffler 13 are fixed to the body 1 at predetermined discrete positions, either directly by bolts and nuts or via appropriate supporting members.

Disposed between the radiator 8 and the exhaust gas purification device 12 is a windbreak plate 15 for preventing an airflow generated by rotation of the radiator fan 10 from blowing onto the exhaust gas purification device 12, and the windbreak plate 15 is positioned so as to face the exhaust gas purification device 12. The windbreak plate 15 is formed from a heat insulating material. In this embodiment, the windbreak plate 15 is erected on the bottom 6 a of the front portion 6 of the ventilation path 5 and has an upper portion 15 a curving toward the exhaust gas purification device 12 and an upper end surface positioned higher than an upper end surface of the exhaust gas purification device 12.

In this embodiment, although the upper portion 15 a of the windbreak plate 15 curves toward the exhaust gas purification device 12, the shape of the windbreak plate 15 is not limited by this embodiment, and the windbreak plate 15 may have any shape so long as the shape renders it possible to prevent a cooing airflow from the radiator fan 10 from blowing onto the exhaust gas purification device 12. For example, a windbreak plate 15′ may be configured so as to extend vertically upward from the bottom 6 a of the front portion 6 of the ventilation path 5 past the upper end surface of the exhaust gas purification device 12, as shown in FIG. 4A, or a windbreak plate 15″ may be configured with an upper portion 15 a″ bending toward the exhaust gas purification device 12 and an upper end surface being positioned higher than an upper end surface of the exhaust gas purification device 12, as shown in FIG. 4B.

The exhaust pipe 11 consists of a first portion 11 a, a second portion 11 b, and a third portion 11 c, in which the first portion 11 a extends from the engine 4 (i.e., an exhaust manifold (not shown) of the engine 4) through the front portion 6 of the ventilation path 5 in the counterweight portion 3 to one end surface 12 a of the exhaust gas purification device 12, the second portion 11 b is on the other end surface 12 b of the exhaust gas purification device 12 and connects the end surface 12 b of the exhaust gas purification device 12 to an end surface 13 b of the muffler 13, and the third portion 11 c extends downward from the other end surface 13 a of the muffler 13 and shifts horizontally so as to protrude to the outside from the rear wall 3 b of the counterweight portion 3.

In this embodiment, the tip of the exhaust pipe 11 protrudes horizontally from the rear wall 3 b of the counterweight portion 3, but the position at which the tip (exhaust port) of the exhaust pipe 11 protrudes from the body 1 is not limited by the embodiment, and, for example, the tip (exhaust port) of the exhaust pipe 11 may protrude upward from the upper wall 3 a of the counterweight portion 3.

Furthermore, in this embodiment, the first to third portions 11 a to 11 c of the exhaust pipe 11 are connected to the end surface 12 a or 12 b of the exhaust gas purification device 12 and/or the end surface 13 a or 13 b of the muffler 13, but the positions at which the first to third portions 11 a to 11 c are connected to the exhaust gas purification device 12 and the muffler 13 are not limited by the embodiment, and for example, the first to third portions 11 a to 11 c may be connected to circumferential surfaces of the ends of the exhaust gas purification device 12 and the muffler 13.

In this embodiment, the ventilation path 5 of the counterweight portion 3 is formed such that the bottom of the rear portion 7 of the ventilation path 5 is lower than the bottom 6 a of the front portion 6, whereby the exhaust gas purification device 12 and the muffler 13 can be compactly accommodated in the space of the rear portion 7 of the ventilation path 5; further, the windbreak plate 15 made from a heat insulating material is provided between the radiator 8 and the exhaust gas purification device 12, whereby, when the forklift is being driven, neither is the exhaust gas purification device 12 subjected to cooling air directly from the radiator fan 10, nor is the radiator 8 subjected to radiation heat straight from the exhaust gas purification device 12, so that both unnecessary cooling of the exhaust gas purification device 12 and unnecessary heating of the radiator 8 can be minimized. Moreover, the exhaust system of the engine 4 can be accommodated in the counterweight portion 3 without reducing the efficiency of purifying exhaust gas by the exhaust gas purification device 12 and the efficiency of cooling by the radiator 8.

Furthermore, in this configuration, the exhaust gas purification device 12 is disposed near the air outlet 5 b of the ventilation path 5, and therefore, the exhaust gas purification device 12 can be accessed readily through the air outlet 5 b, whereby easy maintenance of the exhaust gas purification device 12 can be facilitated. In addition, the rear space of the counterweight portion 3 is utilized as the space to accommodate the exhaust gas purification device 12 and the muffler 13, thereby almost eliminating the need to change existing structures of forklifts, so that the present invention can also be applied to existing forklifts at extremely low costs.

FIG. 5A is a similar view to FIG. 3 and illustrates a variant of the embodiment shown in FIG. 1. This variant differs from the embodiment shown in FIG. 1 simply in the arrangement of the exhaust gas purification device and the muffler. Accordingly, in FIG. 5A, the same components as those shown in FIG. 1 are denoted by the same numerals, and any detailed descriptions thereof will be omitted below.

Referring to FIG. 5A, in this variant, both the exhaust gas purification device 12 and the muffler 13 are disposed in the rear portion 7 of the ventilation path 5 so as to extend vertically and be positioned side by side in the right-left direction of the body 1. In this case, both the exhaust gas purification device 12 and the muffler 13 protrude above the bottom 6 a of the front portion 6 of the ventilation path 5.

Provided between the radiator 8 and the exhaust gas purification device 12 is a windbreak plate 16 made from a heat insulating material and erected on the bottom 6 a of the front portion 6 of the ventilation path 5 so as to face the exhaust gas purification device 12. The windbreak plate 16 extends vertically upward from the bottom 6 a past the upper end surface 12 b of the exhaust gas purification device 12. This variant also renders it possible to achieve similar effects to those achieved by the embodiment shown in FIG. 1.

FIG. 5B is a similar view to FIG. 2 and illustrates another variant of the embodiment shown in FIG. 1. This variant differs from the embodiment shown in FIG. 1 simply in the structure of the ventilation path in the counterweight portion, the arrangement of the exhaust gas purification device and the muffler, the disposition of the windbreak plate, and the position from which the exhaust pipe protrudes to the outside of the body. Accordingly, in FIG. 5B, the same components as those shown in FIG. 1 are denoted by the same numerals, and any detailed descriptions thereof will be omitted below.

Referring to FIG. 5B, in this variant, the lower part of the counterweight portion 3 is occupied by a counterweight or body 9′, and the space above the counterweight or body 9′ in the counterweight portion 3 constitutes a ventilation path 5′. Accordingly, the ventilation path 5′ has a constant height almost across its length. Moreover, both the exhaust gas purification device 12 and the muffler 13 are disposed rearward from the radiator 8 in the ventilation path 5′ so as to extend in the right-left direction of the body 1 and be positioned one above the other with the exhaust gas purification device 12 lying below the muffler 13.

Provided between the radiator 8 and the exhaust gas purification device 12 is a windbreak plate 17 made from a heat insulating material and erected on the bottom of the ventilation path 5′ so as to face the exhaust gas purification device 12. The windbreak plate 17 extends vertically upward from the bottom of the ventilation path 5′ past the upper end surface of the exhaust gas purification device 12. In this case, the upper portion of the windbreak plate 17 may be curved or bent toward the exhaust gas purification device 12. Moreover, in this variant, the third portion 11 c of the exhaust pipe 11 extends upward from one end surface 13 a of the muffler 13 so as to cross the ventilation path 5′, and protrudes upward through the upper wall 3 a of the counterweight portion 3.

In the above embodiment, the industrial vehicle is a forklift, but the industrial vehicle to which the present invention can be applied is not limited to a forklift. Moreover, the present invention can be applied to any industrial vehicle so long as the industrial vehicle includes a work device at the front of the body and a counterweight portion at the rear of the body to balance a load on the work device.

DESCRIPTION OF THE REFERENCE CHARACTERS

-   1 body -   7 fork (work device) -   3 counterweight portion -   3 a upper wall -   3 b rear wall -   4 engine -   5, 5′ ventilation path -   5 a, 5 a′ air inlet -   5 b, 5 b′ air outlet -   6 front portion -   6 a bottom -   7 rear portion -   8 radiator -   9, 9′ counterweight or body -   10 radiator fan -   10 a rotating shaft -   11 exhaust pipe -   11 a first portion -   11 b second portion -   11 c third portion -   12 exhaust gas purification device -   12 b end surface -   13 muffler -   13 a, 13 b end surface -   14 elevated part -   15, 15′, 15″ windbreak plate -   15 a, 15 a′, 15 a″ upper portion -   16 windbreak plate -   17 windbreak plate 

The invention claimed is:
 1. An industrial vehicle comprising: a work device attached at a front of a body; a counterweight portion for balancing a load on the work device, the counterweight portion being disposed at a rear of the body and having a ventilation path provided therein so as to extend in a front-rear direction of the body; an engine attached to the body as a power source and disposed forward from the counterweight portion; a radiator disposed rearward from the engine so as to be positioned immediately before a front end opening of the ventilation path or at a front portion of the ventilation path; a radiator fan for cooling the radiator, the radiator fan being disposed between the engine and the radiator and allowing an airflow generated by rotation of the radiator fan to be exhausted to the outside of the body through the ventilation path; an exhaust pipe supported by the body, connected to the engine at one end, and protruding from the rear of the body to the outside at the other end; and an exhaust gas purification device and a muffler provided at some positions along the exhaust pipe, wherein, an elevated part is formed between bottoms of the front and rear portions of the ventilation path, whereby the bottom of the rear portion is lower than the bottom of the front portion, the exhaust gas purification device and the muffler are disposed in the rear portion of the ventilation path so as to be positioned one above the other with the exhaust gas purification device lying above the muffler and at least partially protruding above the bottom of the front portion of the ventilation path, and a windbreak plate for preventing the airflow from blowing onto the exhaust gas purification device is disposed between the radiator and the exhaust gas purification device so as to face the exhaust gas purification device, the windbreak plate being formed from a heat insulating material, and the windbreak plate being erected on the bottom of the front portion such that the windbreak plate has an upper end surface positioned higher than an upper end surface of the exhaust gas purification device.
 2. The industrial vehicle according to claim 1, wherein at least an upper portion of the windbreak plate is bent or curved toward the exhaust gas purification device.
 3. The industrial vehicle according to claim 1, wherein both the exhaust gas purification device and the muffler have a cylindrical outer shape and extend in the right-left direction of the body.
 4. The industrial vehicle according to claim 1, wherein the industrial vehicle is a forklift. 